Children who have serious emotional disturbances often become utilizer of multiple service systems. Children in varied ethnic groups with the same degree of psychiatric impairment may be relegated to mental health or juvenile justice service systems on the basis of ethnicity alone. The purpose of this study is to use a multi-system data base in King County, Washington, to 1) describe the juvenile justice involvement of youth in the mental health system, 2) describe juvenile justice and mental health system involvement for two system versus one system youth, 3) for two system before and after mental health treatment, and 4) describe how youth from ethnic subgroups who are within the mental health system differ in their patterns of juvenile justice involvement. Increased knowledge about when children with mental disorders are most vulnerable to juvenile justice involvement is necessary to improve the organization, delivery, and accessibility of needed services to young people. The proposed study incorporates both retrospective and prospective design to document experiences within the juvenile justice system for a cohort of 650 children over 10 years of age consecutively admitted to the King County Mental Health System in 1992. Type of involvement (i.e., number of referrals, seriousness of offenses, case dispositions, length of stay in detention) will examined for the period two years prior to and two years after a subject's date of entry into the mental health system. Service utilization by youth across different ethnic groups will be compared.